Intraluminal stenting graft

ABSTRACT

An intraluminal stenting graft for implantation in a blood vessel and a method for making same wherein the intraluminal stenting graft includes a collapsible tube member having a first end and a second end. An outer layer and an inner layer extend between the ends. The outer layer is more flexible than the inner layer. The outer layer is joined to the inner layer to form a plurality of cylinders longitudinally extending between the first end and the second end. The method of the present invention including the steps of: placing a first layer of material on a substantially flat surface; placing a second layer of material on a shaped surface; maintaining the second layer on said shaped surface by use of reverse pressure; moving the second layer to the first layer; joining the second layer to the first layer to form a plurality of longitudinally extending cylinders; and shaping the first and second layers to form a tube member.

BACKGROUND OF THE INVENTION

The present invention is directed to an intraluminal stenting graft.More specifically, the invention is directed to an intraluminal stentinggraft for implantation in a blood vessel including a collapsible tubemember formed from a plurality of cylinders. The invention is furtherdirected to a method for making such a stenting graft.

Intraluminal stenting grafts are known in the art. An example of anintraluminal stenting graft/stent is disclosed in U.S. Pat. No.5,156,620, which is incorporated herein by reference. Intraluminalstenting grafts are implanted in a blood vessel to repair, for example,aortic aneurysms. They are also used to support sections of a bloodvessel that are diseased or have become narrowed by arteriosclerosis.

DISCLOSURE OF INVENTION

The present invention is directed to an intraluminal stenting graft forimplantation in a blood vessel and a method for making same. Theintraluminal stenting graft includes a collapsible tube member having afirst end and a second end. An outer layer and an inner layer extendbetween the ends. The outer layer is more flexible than the inner layer.The outer layer is joined to the inner layer to form a plurality ofcylinders longitudinally extending between the first end and the secondend.

The method of the present invention includes the steps of:

(a) placing a first layer of material on a substantially flat surface;

(b) placing a second layer of material on a shaped surface;

(c) maintaining the second layer on said shaped surface by use ofreverse pressure;

(d) moving the second layer to the first layer;

(e) joining the second layer to the first layer to form a plurality oflongitudinally extending cylinders; and

(f) shaping the first and second layers to form a tube member.

The primary object of the present invention is to provide anintraluminal stenting graft that is efficient.

An important object of the present invention is to provide anintraluminal stenting graft that is relatively easy to use.

Other objects and advantages of the invention will become apparent upona review of the accompanying drawings and the following detaileddescription of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of an intraluminalstenting graft according to the present invention;

FIG. 2 is a cross-sectional view of the plurality of cylinders of thepresent invention taken along line 2--2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2 showingthe one-way valve of the present invention positioned in the opening inthe end wall of the tube member;

FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2 showingone of the cylinders according to the present invention;

FIG. 5 is a cross-sectional view of the intraluminal stenting graft ofthe present invention positioned in a blood vessel at the site ofimplantation in a collapsed condition;

FIG. 6 is a cross-sectional view similar to the view of FIG. 5 showingthe intraluminal stenting graft implanted in a blood vessel;

FIG. 7 is a second embodiment of an intraluminal stenting graftaccording to the present invention;

FIG. 8 is a side elevational view of the first layer of material on aplaten being treated according to the method of the present invention;

FIG. 9 is a side elevational view showing the second layer of materialon a shaped surface being maintained on the surface by reverse pressureaccording to the method of the present invention;

FIG. 10 is a view similar to the view of FIG. 9 showing the joining ofthe second layer to the first layer; and

FIG. 11 is a side elevational view showing the second layer joined tothe first layer.

BEST MODE FOR CARRYING OUT INVENTION

Referring now to the drawings, the present invention will now bedescribed in detail. Referring to FIGS. 1 and 2, the intraluminalstenting graft of the present invention is indicated by the referencenumber 10. The stenting graft 10 includes a collapsible tube member 12having a first end 14 and a second end 16. An outer layer of material 18and an inner layer of material 20 extend between said first end 14 andsaid second end 16. A first end wall 22 extends between the outer layer18 and the inner layer 20 at the first end 14. A second end wall 24extends between the outer layer 18 and the inner layer 20 at the secondend 16.

As shown in FIGS. 1, 2 and 4, the outer layer 18 is joined to the innerlayer 20 to form a plurality of cylinders 30 that extend longitudinallybetween the first end 14 and the second end 16. As shown in FIG. 1, thetube member 12 can include a radially extending chamber 32 that is incommunication with the plurality of cylinders 30. In the presentembodiment, the chamber 32 is positioned adjacent the first end 14.However, it should be understood that the chamber 32 can be positionedin a variety of locations along the length of the chamber.

Referring to FIG. 1, the tube member 12 can include an opening 40 in thefirst end wall 22. The opening 40 can receive a fluid, such as air. Asdescribed below, the fluid causes the collapsed tube member 12 to expandfor implantation in a blood vessel. As shown in FIG. 3, a one-way valve42, such as a check valve, can be positioned in the opening 40. Thevalve 42 allows for the introduction of the fluid into the tube member12. The valve prevents the escape of the fluid from the tube member 12after introduction into the tube member. The fluid can be introducedinto the tube member 12 through the valve 42 by a fluid conduit 44.

Referring to FIG. 2, the outer layer 18 and the inner layer 20 arecomposed of a polymer material that is biocompatible. An example of sucha material is polytetrafluoroethylene. The outer layer 18 is constructedof a more flexible or lighter weight material than the inner layer 20.This allows the outer layer 18 to be more compliant when the tube member12 is expanded. The inner layer 20 can be treated or coated with amaterial such as expanded polytetrafluoroethylene (ePTFE) to create asurface more conducive to blood flow.

As shown in FIG. 2, each of the cylinders 30 includes a centerline Cthat extends longitudinally through the cylinder when the tube member 12is in an expanded condition. The centerline C is a point from which tworadii R₁ and R₂ extend. The radii R.sub. and R₂ define an angle β. Theangle β can be an obtuse angle being more than 90° and less than 180°.When the plurality of cylinders 30 are positioned adjacent one anotherto form the tube member 12, as shown in FIG. 2, the radius R₁ of, one ofthe cylinders bisects the radius R₂ Of the adjacent cylinder. Thisarrangement causes the plurality of cylinders 30 to cooperate tomaintain the tube member 12 in a stable, expanded condition forimplantation in a blood vessel. It has been found that the greatercompliance of the outer layer 18 and the greater amount of material ofthe outer layer 18 as compared to the inner layer 20 causes the angle βto be less than 180°. When the tube member 12 is expanded, the pluralityof cylinders 30 interfere with one another to force the tube member intoa round configuration as shown in FIG. 1. This provides an open pathway46 for the flow of blood in a blood vessel.

Referring now to FIGS. 5 and 6, the intraluminal stenting graft 10 ofthe present invention is implanted in a blood vessel 50 by manipulatingthe collapsed tube member 12 through the vessel to an implantation site52. The tube member can be manipulated by the conduit 44, which is incommunication with the valve 42, or by some other suitable apparatus. Asshown in FIG. 6, when the stenting graft 10 is in the proper position,fluid from the conduit 44 is introduced through the opening 40 and intothe chamber 32 and cylinders 30. The chamber 32 allows for an efficientdistribution of fluid into the cylinders 30. As described above, theplurality of cylinders 30 and the outer and inner layers 18 and 20,respectively, cooperative to maintain the tube member 12 in a round andopen configuration. After filling, the conduit 44 is removed. Thestenting graft 10 allows blood flow through the pathway 46 at the siteof implantation 52.

A second embodiment of the intraluminal stenting graft 10 of the presentinvention is shown in FIG. 7. The stenting graft 10 includes a trunkportion 60 and branch portions 62 and 64. This embodiment can be used,for example, at the bifurcation of the aorta and lilac arteries. Thetrunk portion 60 can be positioned in the aorta and the branch portions62 and 64 can be positioned in the lilac arteries. Many otherconfigurations can be constructed depending on the application.

Referring now to FIGS. 8 through 11, the method for manufacturing anintraluminal stenting graft according to the present invention will bedescribed in detail. Referring to FIG. 8, a first layer of material 70,which corresponds to the inner layer 20, is placed on a flat surfacesuch as a platen 72. A bonding agent such as adhesive 76 is applied tothe first layer 70 by applicators 78.

As shown in FIG. 9, a second layer of material 80, which corresponds tothe outer layer 18, is placed on a shaped surface 82. The shaped surface82 includes longitudinally extending indentations 84 having, forexample, partially cylindrical shapes. The indentations include acoating 86 of synthetic resin polymers and products, such as Teflon®, toprevent the second layer 80 from adhering to the shaped surface 82. Thesecond layer 80 is maintained on the shaped surface 82 by the use ofreverse pressure or vacuum created by a reversible pump P.

As shown in FIG. 10, the second layer 80 is moved to the first layer 70.The layers 70 and 80 are fixedly joined together by the adhesive 74. Thelayers can also be joined by a heat sealing process (not shown).

As shown in FIG. 11, the joining of the first layer 70 to the secondlayer 80 forms a plurality of longitudinally extending cylinders 30, asdescribed above. A chamber 30, end walls 22 and 24 and opening 40 canalso be formed in the method. The longitudinally extending ends of thejoined layers can be brought together and joined by adhesive orotherwise to form the cylindrical tube member 12 shown in FIGS. 1 and 5.

The first layer 70 and second layer 80, as used in the method, can beconstructed of a polymer material, as described above for the outerlayer 18 and inner layer 20. The second layer 80 is more flexible and islighter weight than the first layer 70. The cylinders 30 that are formedas a result of the method have the same characteristics as describedabove concerning the centerline C, radii R₁ and R₂ and the angle β beingless than 180°.

The present invention can be modified and changed in a variety of wayswith the scope of the invention being defined by the appended claims.

We claim:
 1. An intraluminal stenting graft for implantation in a bloodvessel, comprising:a collapsible tube member having a first end and asecond end; an outer layer and an inner layer extending between saidends, said outer layer being more flexible than said inner layer, saidouter layer being joined to said inner layer to form a plurality ofcylinders longitudinally extending between said first end and saidsecond end, said plurality of cylinders being positioned adjacent oneanother to form said tube member, said plurality of cylinders providingstructural support to said tube member; first and second end wallsextending between said outer layer and said inner layer at said firstand second ends, respectively, one of said end walls including anopening for receiving a fluid; and a valve positioned in said opening toallow for introduction of said fluid into said tube member and toprevent escape of said fluid from said tube member.
 2. The intraluminalstenting graft of claim 1, wherein said fluid is air.
 3. Theintraluminal stenting graft of claim 1, wherein each of said cylindersincludes a centerline longitudinally extending through said cylinder,said centerline being a point from which two radii extend, said radiidefining an angle, said angle being less than 180°.
 4. The intraluminalstenting graft of claim 3, wherein said plurality of cylinders arepositioned adjacent one another to form said tube member, said radii ofone of said cylinders bisecting respective radii of an adjacentcylinder, said cylinders cooperating to prevent said plurality ofcylinders from collapsing after said tube member has been expanded. 5.The intraluminal stenting graft of claim 1, wherein said inner and outerlayers are comprised of a polymer material.
 6. The intraluminal stentinggraft of claim 5, wherein said material of said outer layer is lighterthan the material of said inner layer.